A vehicle traveling along a roadway may pass through varying types and concentrations of emissions from other vehicles. Users may manually control the ventilation system intakes to limit the intake of emissions into the vehicle. As most of these emissions may be invisible, it may be difficult for a driver to determine when the vehicle ventilation system intakes should be closed and/or when the system blower or impeller should be turned off or down. The vehicle may be immersed in a high-concentration emission zone before the driver can react by switching the ventilation system to “recirculate”. Also, because the concentrations of emissions in the path of the vehicle are constantly varying, it may be difficult to manually control the ventilation system so as to prevent or limit intake of high concentrations of emissions into the vehicle.